Graphite-SiOx Electrodes with a Biopolymeric Binder for Li-Ion Batteries: Predicting the Cycle Life Performance from Physical Properties

Low-environmental-impact binder systems are required for lithium-ion battery electrodes that exhibit good cohesive and adhesive strengths, flexibility, optimized microstructures for ions, and electronic conductivities. In this work, carrageenan gum is employed as a green binder system for graphite-SiOx anodes of various physical characteristics (porosity and active mass). A simple current interrupt test is used to elucidate the contributing ohmic and charge transfer resistances, showing increase in both, related to the mass loading, porosity, and state of charge. The contribution of SiOx to the reversible capacity was observed to fade in the first 20–30 cycles. To describe the cycle life, an empirical model that directly relates the porosity and mass loading to the cycle life is presented. A relationship between the physical and electrochemical properties has been explored to achieve maximum cycle life. This method may enable faster screening of electrode formulations and prediction of cycle life of this and other electrode types.